This complex disease is a whole clinical disorder
which can be caused by the family of the various herpes virus. Rhinopneumonie
will result in respiratory disorders, abortion or nervous demonstrations
(it depends on the virus). This disease is specific to equids and
can not be transmitted to other species of animal or human's.

Contamination

Several types of herpes viruses were identified in
equids, but three of them cause respiratory disorders, and are the
origin of the pathology called herpes virus equine:

 Equine Herpes virus type 1 (or EHV1) responsible for respiratory
disorders close to equine influenza, and which can cause abortions
in the latter part of gestation and nervous disorders sometimes
very serious.
 Equine Herpes virus type 4 (or EHV4) less virulent than the
EHV1, but causing infections in the bronchial tubes.
 Herpes virus type 2 (or EHV2) relatively benin, but suspected
to support the bacteria or viral attacks of the respiratory tracts.

It is a contagious disease, the virus being transmitted by respiratory
tract to the other equids in the majority of the cases. The puny
specimen, and all that could be soiled in the time of foaling can
also contribute to the propagation of the virus.
The characteristic of these viruses is that they can stay a very
long time in a latent state, often persist all the life in the organism,
and can be reactivated by another disease, i.e.: stress...
That explains why the rate of infection of the herpes virus is very
high in the equine population, and can reach more than 80% in a
breeding.

The virus initially will multiply in the mucous membranes of the
nose, the pharynx and the trachea, and then in the lymphs nodes.
From there, the virus will be spread in the respiratory tract but
also can go to other organs like uterus and/or the central nervous
system. According to the localisation of the virus, a lot of various
clinical signs will appear.

Symptoms

The symptoms of the equine herpes virus are similar to equine influenza,
i.e.: strong fever, cough; initially clear nasal discharge, then
thicker. But, often these symptoms are very discreet on the adults
and often they can not be detected.
For young or old donkeys, bacterial complications can lead to bronchopneumonia
or a chronic disease.

The most serious consequences relate to mares at the end of gestation
infected by virus EHV1. Indeed, if the mare contracts the disease
during her gestation, she could abort.

Nervous complications can also appear approximately a week after
the respiratory symptoms. They appear by disorderly movements and
behaviour of the animal. In the most severe cases, the donkey can
be struck down with posterior paralysis and be in a position called
"dog sitting", or be struck down with general paralysis
(the worst prognosis). After-effects can persist after curing, it
depends on the brain or spinal cord lesions.

Prevention - Treatment

There is no treatment against the equine herpes virus,
and only the infection and any complications can be treated.
The prevention is the vaccination, the isolation of the sick donkey
and especially the mare's who had an abortion. If there is an abortion
in the breeding, you have to put all donkeys in quarantine and sanitary
measure must be applied: disinfect all the buildings, material...